UNITED STATES DEPARTMENT OF AGRICULTURE 
. Jl BULLETIN No. 939 
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Contribution from the Bureau of Animal Industry 
JOHN R. MOHLER, Chief 
Washington, D. C. 
April 23, 1921 
THE TURKEY AN IMPORTANT FACTOR IN THE 
SPREAD OF GAPEWORMS. 1 
By B. H. Ransom, Chief, Zoological Division. 
CONTENTS. 
Page. 
Examination of market chickens 
and turkeys 
Experimental work 
Factors in the spread of gape- 
worms 
Investigations on Maryland 
farms 
Significance of turkeys in relation 
to gapes formerly unrecognized — 
Turkey the preferred host of the 
gapeworm 
How to avoid losses in chickens 
Conclusions 
List of references 
Page. 
10 
10 
11 
12 
13 
EXAMINATION OF MARKET CHICKENS AND TURKEYS. 
pOR THE PURPOSE of collecting some statistics on the preva- 
lence of gapeworms (Syngamus trachealis) in the vicinity of 
Washington, D. C., and of obtaining material for use in experiments, 
examinations were made of the tracheas of 635 chickens killed for 
sale at poultry stalls in Center Market during the latter half of 
December, 1916, and the months of January and February, 1917. 
Nothing definite is known as to the ages of these chickens except 
that the chickens were all obviously large enough for food purposes. 
Probably none were less than six months old, most of them likely 
were older, and no doubt many were a year old or more. No gape- 
worms were found. 
At the same time the tracheas of turkeys from the same market 
were similarly examined. The ages of the turkeys, as in the case of 
the chickens, were uncertain, but undoubtedly all the turkeys were 
at least 6 months old, and many of them were probably more than a 
year old. During the period mentioned the tracheas from 386 tur- 
keys were examined. The next year, beginning March 2, 1918, an- 
1 The writer is greatly indebted to Dr. Lawrence Avery, of the Bureau of Animal In- 
dustry, for assistance rendered in carrying out the investigations reported in this paper. 
22888°— 21— Bull. 039 1 
